>>But you're not his parent, so presumably you don't have to worry about all those other more important issues. If you fuss at a teen about everything he or she does that bugs you, you'd have no other communication.
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>>Well, actually (in this instance), I've been asked to step in and be "de-facto" parent, so I've had to deal with a few important issues.
>>
>
>In that case, I'd focus on much more important stuff than slang and grammar. Surround him with proper English and he'll learn it whether he uses it or not.
>
>Tamar

It's interesting that my elder daughter (11) has quite a "posh" accent while my youger (7) speaks with the local southern accent (we call it "Estuary English" as in that spoken around the Thames estuary). Now I have a distinctively posher accent than my younger brother. Hmmmmm